A Novel SnO2 Sensor and its Selectivity Improvement with Catalytic Filter

Abstract : We present a new organometallic approach for the preparation of nanostructured SnO2 gas sensitive layer. The deposited sensitive layer on a silicon device shows high response to 100 ppm of CO and C3H8. In order to improve the sensor selectivity we have implemented a catalytic filter material in a cap placed just above the sensing device. The catalytic filter is made of zinc oxide supported gold nanoparticles (Au@ZnO) prepared by deposition-precipitation by urea (DPU) method. This catalytic filter, operated at room temperature and under humid atmosphere (HR 50%), allowed to selectively eliminate the sensor response under 100 ppm of CO, whereas the sensor always responds to 100 ppm of C3H8.